[BUG] Odd warning in generated .c file related to fused type usage

[skunkyevil]

Describe the bug

There's an odd warning present when I check for fused type in if clause.
Warning C4244 '=': conversion from 'long' to 'char', possible loss of data

I found mention of the same bug in Internet dated 2015:
https://www.mail-archive.com/cython-devel@python.org/msg04553.html

I minimized the example code

Code to reproduce the behaviour:

ctypedef fused floating:
    float
    double

cpdef add_one(floating [:] array):
    if floating is float:
        pass
        

Copilled with:

from setuptools import setup
from Cython.Build import cythonize

setup(
    name='Hello world app',
    ext_modules=cythonize("bug.pyx"),
)

Expected behaviour

There should be no warning

OS

Windows 10

Python version

3.9

Cython version

3.0.5

Additional context

No response

[scoder]

What warning message do you get?

[skunkyevil]

Sorry, it was Warning C4244 '=': conversion from 'long' to 'char', possible loss of data. Updated above

[da-woods]

Probably from

cython/Cython/Compiler/FusedNode.py

Line 467 in bc32b7e

kind = ord(dtype.kind)

(where kind is a char and ord returns a long). PR welcome to fix - I think this could hide a real bug in principle. (At least if Numpy starts using unicode kinds - which would be odd but I guess they could)

[scoder]

Ah, thanks. So this is from generated code on our side. I replaced the char type with Py_UCS4 in e584c46. It comes from a Unicode string, there's no reason why we should cut this down to a char.